Color/temp shift from left to right

I returned my original with perfect screen but unusually poor battery performance today..

This new unit is draining far less quickly... But clearly has a shift in color most noticeable on the keyboard--left side keys are dark slate gray, right keys more tan, warmer. Obvious on white screen too. Really bugging me , girlfriend can't see it.

Thoughts? Do i go argue for #3 and hope they don't call me crazy and make me pay theb$35/restock fee?

Right! I"m just afraid it's so subtle the reps will claim it isn't a physical defect and make me pay. They gave me a hard time about the battery on the last one, despite the fact I provided screenshots of the full battery cycles showing poor performance with no explanation for it. Said normally they have to "wipe it, then replicate the problem" which would have entailed....keeping the phone and using it like I would, or something? :-P But they were nice enough and said they'd "take care of me." All of which makes me leery of doing it again. But It will DRIVE ME CRAZY, so in I go tomorrow once again!

(Looking at Note 4 reviews in the meantime, remembering that this is the pain of the early adopter)

If still defective, and a factory reset can't solve it due to it not being a software issue, I'd return for new
think of it as feedback to a company

while those people who would keep theirs due to inconvenience or other reasons, the manufacturer will think "oh we did a great job on quality control, not many returns"
but no, they need to know of these things so that they improve and get better